Accidental chemical explosions

For fixed or mobile sources of explosions, or for sources of hazardous cloud, the distance from the source of an explosion can be evaluated deterministically or probabilistically with the method given in Ret [20]. If it is not possible to locate the plant in an area where the risk is not significant, the plant should be protected against these events. 

The design can follow the approach of an equivalent explosion of TNT, particularly if the source is relatively far from the facility. For this purpose, two coefficients are applied to the identified mass of explosive material  

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Process Safety A discipline that focuses on the prevention and mitigation of fires, explosions, and accidental chemical releases at process facilities. Excludes classic worker health and safety issues involving working surfaces, ladders, protective equipment, etc. 

Emergency response plan A written plan which addresses actions to take in case of plant fire, explosion or accidental chemical release. 

The equipment and systems of the processing phuit are designed to contain tlie chemicals mider processing conditions and to provide tlie controlled environment required for production. This equipment is designed to function under both specific process conditions and upset conditions. Upset conditions tliat are considered in design include fire, explosions, and accidental chemical releases. 

Both ACC and SOCMA have programs to promote good practices among their member companies in the area of chemical process safety.59 In 1989, ACC developed the Responsible Care Process Safety Code60 to prevent fires, explosions, and accidental chemical releases. The code and its accompanying resource guidelines include a series of recommended management practices. 

Process safety, a discipline that focuses on the prevention of fires, explosions and accidental chemical releases at chemical process facilities, is a key element for a sustainable industrial chemistry, as indicated in the previous sections. There are three key elements for process safety behavior, system and process. 

API RP 750 Section 5 American Petroleum Institute Recommended Practice 7S0 OSHA 29 CFR 1910.119 Process Safety Management of Highly Hazardous Chemicals, Explosives, and Blasting Agents BPA 40 CFR Part 68.28 Risk Management Programs for Chemical Accidental Release Prevention Proposed Rule... 

The production of nuclear power requires other operations, such as fuel fabrication. This has caused a few accidental releases of radioactivity, most notably when errors were made that allowed chemical nuxtures to reach nuclear criticahty. Such situations create a chain reaction for only a short time because of the small amounts of fissile material available. However, woikers and ai one else in the vicinity can be exposed to the radiation field or to the fission and activation products, such as 1 or Xe (half-life = 5 days). Most of these accidents occurred prior to 1965, but even in 1999 there was a criticality accident at Tokaimura in Japan where three woikers were severely injured. One of the most severe environmental releases of radioactivity followed a chemical explosion at the Mayak complex near Kyshtym, Russia, in 1957, where about 74 PBq of fission products were released, which contaminated about 15,000 km. ... 

Lead-bismuth coolant reacts very slightly with water and air. Progression of accidental processes caused by failures of primary circuit tightness and steam generator (SG) inter-circuit leaks takes place without hydrogen release or exothermic reactions. In addition, there are no materials within the core and the reactor installation that release hydrogen as a result of thermal or radiation effects, or chemical reactions with the coolant. Therefore, the likelihood of chemical explosions and fires as internal events is virtually eliminated. 

The Process Safety Code was adopted in 1990 and is designed to reduce the risk of fires, explosions, and accidental chemical releases. It requires plants to ... 

Each laboratory should be equipped with a trip alarm to indicate evacuation in the event of accidental chemical spills or explosion. 

Hypergolic A hypergolic mixture ignites upon contact of the components without any external source of ignition (heat or flame). The only field, in which this is a desirable event, is in rocket fuel research. Accidental mixing of incompatible materials can lead to a fire or explosion. Here is one example provided by the staff at ILPI of what can happen, when incompatibles are mixed. Always read the labels on your bottles (don t assume a chemical s identity by the shape, size, or color of the bottle), and know what materials are incompatible with the chemicals that you are using. 

Developed under tlie Clean Air Acts (CAA s) Section 112(r), tlie Risk Management Program (RMP) rule is designed to reduce tlie risk of accidental releases of acutely toxic, flanunable and explosive substances. USEPA finalized its list of regulated substances (138 chemicals) and defined tlireshold quantities for these chemicals. 

Modem methods for the manuf and storage of expl materials, which include many exotic chemicals, fuels, and propints, allow less space for a given quantity of expl material than previously permitted. Such concns of expls increase the possibility of the propagation of accidental explosions (one accidental explosion causing the detonation of other expl materials). It was evident that a requirement for more accurate design techniques had become essential. Ref 3 describes a rational design method to provide the required structural protection. It presents methods of design for protective construction... 

Half-lives span a very wide range (Table 17.5). Consider strontium-90, for which the half-life is 28 a. This nuclide is present in nuclear fallout, the fine dust that settles from clouds of airborne particles after the explosion of a nuclear bomb, and may also be present in the accidental release of radioactive materials into the air. Because it is chemically very similar to calcium, strontium may accompany that element through the environment and become incorporated into bones once there, it continues to emit radiation for many years. About 10 half-lives (for strontium-90, 280 a) must pass before the activity of a sample has fallen to 1/1000 of its initial value. Iodine-131, which was released in the accidental fire at the Chernobyl nuclear power plant, has a half-life of only 8.05 d, but it accumulates in the thyroid gland. Several cases of thyroid cancer have been linked to iodine-131 exposure from the accident. Plutonium-239 has a half-life of 24 ka (24000 years). Consequently, very long term storage facilities are required for plutonium waste, and land contaminated with plutonium cannot be inhabited again for thousands of years without expensive remediation efforts. 

Vessel mptures can also occur when a higher-temperature liquid or solid is combined with a cooler low boiling liquid, transferring sufficient heat from the hotter material to the colder material such that the colder material rapidly vaporizes. No chemical reactions are involved instead, the explosion occurs because the cooler liquid expands as it is converted to vapor, creating high pressures. These are called physical explosions. A common example is a steam explosion, which occurs when liquid water is accidentally introduced into a process vessel operating at an elevated temperature. If the hotter material is above the superheat limit temperature of the evaporating liquid, initial confinement by a vessel is not required to create an explosion pressure wave. 

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